了解更年期的演变提出了一个长期存在的科学挑战1,2,3-为什么女性应该在自然寿命结束之前停止排卵?在人类社会中,代际资源转移,例如,食物分享和照顾,被认为在更年期的演变中发挥了关键作用,提供了一条途径,使生育后的女性可以增强其亲属的健康。4,5,6迄今为止,其他晚育女性可能提供其亲属的晚年贡献尚未得到很好的研究。这里,我们检验了以下假设:繁殖后的雌性常住虎鲸(Orcinusorca)通过减少其遭受的社会伤害来为其后代提供社会支持。我们发现社会伤害,由齿耙标记量化,在生育后的母亲面前,雄性后代的比例较低。相比之下,我们没有发现证据表明生育后的母亲减少了女儿的耙纹。同样,我们发现没有证据表明生殖母亲或祖母(生殖或生殖后)减少了后代和生殖的社会伤害,分别。此外,我们发现,繁殖后的雌性对减少不是其后代的鲸鱼在其社会单位中的耙痕没有影响。一起来看,我们的结果突出表明,指导晚年支持可能是生育后女性将社会利益转移给男性后代的关键途径.
Understanding the evolution of menopause presents a long-standing scientific challenge1,2,3-why should females cease ovulation prior to the end of their natural lifespan? In human societies, intergenerational resource transfers, for example, food sharing and caregiving, are thought to have played a key role in the evolution of menopause, providing a pathway by which postreproductive females can boost the fitness of their kin.4,5,6 To date however, other late-life contributions that postreproductive females may provide their kin have not been well studied. Here, we test the hypothesis that postreproductive female resident killer whales (Orcinus orca) provide social support to their offspring by reducing the socially inflicted injuries they experience. We found that socially inflicted injuries, as quantified by tooth rake marks, are lower for male offspring in the presence of their postreproductive mother. In contrast, we find no evidence that postreproductive mothers reduce rake marking in their daughters. Similarly, we find no evidence that either reproductive mothers or grandmothers (reproductive or postreproductive) reduce socially inflicted injuries in their offspring and grandoffspring, respectively. Moreover, we find that postreproductive females have no effect on reducing the rake marks for whales in their social unit who are not their offspring. Taken together, our results highlight that directing late-life support may be a key pathway by which postreproductive females transfer social benefits to their male offspring.